Introduction of Nestia

Nestia: The Ultimate TypeScript SDK Generator for NestJS Applications

Introduction

Nestia is a revolutionary TypeScript SDK generator and runtime validator for NestJS applications, designed to eliminate redundant schema definitions and enhance development efficiency. Unlike traditional approaches that require multiple schema declarations, Nestia leverages pure TypeScript types to provide comprehensive validation and API documentation.

The Problem Nestia Solves

Traditional NestJS development faces several challenges:

Triple schema definition requirement (TypeScript type, class-validator, @nestjs/swagger)
Runtime-only validation errors that escape TypeScript compilation
Performance overhead from class-validator and class-transformer
Complex validation rule definitions

Key Features and Benefits

Pure TypeScript Approach

// Traditional NestJS approach with class-validator
export class ArticleDto {
  @IsString()
  @IsUUID()
  @ApiProperty({ format: "uuid" })
  id!: string;

  @IsOptional()
  @IsString()
  @MinLength(5)
  @MaxLength(100)
  @ApiProperty({ nullable: true })
  title?: string;
}

// Nestia's pure TypeScript approach
export interface IArticle {
  id: string & tags.Format<"uuid">;
  title?: string & tags.MinLength<5> & tags.MaxLength<100>;
}

Performance Benefits

Nestia offers remarkable performance improvements:

Validation: 20,000x faster than class-validator
JSON Serialization: 200x faster than class-transformer
Zero runtime overhead through AOT compilation
Optimized memory usage

SDK Generation

// Automatic type-safe SDK generation
const sdk = createAxiosSDK<typeof MyController>();

// Type-safe API calls
await sdk.articles.store({
  title: "Hello World",
  body: "Content",
  files: []
});

Enhanced Validation System

Pure TypeScript interface-based validation
Compile-time type checking
Built-in type-level validation rules
Automatic error message generation

Getting Started

Installation

npm install @nestia/core
npm install -D @nestia/sdk

# Configure tsconfig.json
{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

Basic Usage

import { TypedBody, TypedRoute } from "@nestia/core";
import { Controller } from "@nestjs/common";

@Controller("articles")
export class ArticlesController {
  @TypedRoute.Post()
  public async store(
    @TypedBody() input: IArticle.ICreate
  ): Promise<IArticle> {
    return {
      ...input,
      id: "uuid-here",
      created_at: new Date().toISOString()
    };
  }
}

Advanced Features

Type-Safe HTTP Requests

interface IArticle {
  id: string & tags.Format<"uuid">;
  title: string & tags.MinLength<3> & tags.MaxLength<50>;
  body: string;
  files: IAttachmentFile[];
  created_at: string & tags.Format<"date-time">;
}

Performance Analysis

Benchmark Results

Comparative performance metrics:

Validation Speed
- Nestia: 2,000,000 ops/sec
- class-validator: 100 ops/sec
- Improvement: 20,000x faster
JSON Serialization
- Nestia: 200,000 ops/sec
- class-transformer: 1,000 ops/sec
- Improvement: 200x faster